Bitterblossom is very useful in the control match where everything revolves around as much damage as you can possibly inflict. It effectively prevents spot removal from stunting your resources as each turn you get a creature out of it. They are uncounterable, which also helps a great deal. Being a stationary form of creature production, it is hard to argue how good Bitterblossom can be once it lands. The additional Bitterblossoms are there in the sideboard to supplement the other two in the control (and "Counter-Top") match early on.
Spinning Darkness is one of my favorite cards in the deck. With the removal the deck already packs, it gets that much better against "Zoo". Here, you're gaining life and knocking off one of their creatures. It also can shrink Tarmogoyf, which is the least of your worries anyway; that card should never stick against you.
I've found Dystopia to be ultra-effective in the "Armageddon Stax" match, as well as any other deck running white or green permanents (Elspeth, Enchantress, etc.) to a large extent. It is just a potent weapon that again - works as a stationary form of production.

